Hippocampal Circuitry Flashcards
what are the four regions of the hippocampus
CA1, CA2, CA3, CA4
what are the pyramidal cells
main excitatory neuron in the hippocampus
what are inhibitory interneurons
multiple types of GABAergic neurons
what is the dentate gyrus
forms a small C shape along the hippocampal sulcus, facing the CA4 end of the hippocampus
what are the neurons in the dentate gyrus
granule cells and inhibitory interneurons
what are granule cells
main excitatory neurons in the dentate gyrus
describe the flow of information in the hippocampus
carried via a sequence of excitatory synapses; information that enters the dentate gyrus travels primarily in one direction through the hippocampus
what is the hippocampal circuitry pathway
endorhinal cortex (layer 2) –> dentate gyrus –> CA3 –> CA4 –> subiculum –> endorhinal cortex (layer 5 and 6)
what is the perforant path
cell bodies : pyramidal cells in entorhinal cortex
project to : dentate gyrus (go across hippocampal sulcus)
what is the mossy fiber pathway
cell bodies : dentate granule cells
project to : CA3 pyramidal cells
what is the schaffer collateral pathway
cell bodies : CA3 pyramidal cells
project to : CA1 pyramidal cells
what is the subiculum
transitional cortical region between the CA1 end of the hippocampus and the entorhinal cortex
what are the hippocampal efferents
alveus
fimbria
fornix
hippocampal commissure
what is the fimbria
axons traveling along the outside of the hippocampus that enter the fornix
what is the fornix
axons projecting from the fimbria to the mammillary bodies and other areas
